source: trunk/src/xmlpatterns/expr/qarithmeticexpression.cpp@ 679

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#include "qboolean_p.h"
#include "qbuiltintypes_p.h"
#include "qcommonsequencetypes_p.h"
#include "qemptysequence_p.h"
#include "qgenericsequencetype_p.h"
#include "qliteral_p.h"
#include "qpatternistlocale_p.h"
#include "qschemanumeric_p.h"
#include "quntypedatomicconverter_p.h"

#include "qarithmeticexpression_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

ArithmeticExpression::ArithmeticExpression(const Expression::Ptr &op1,
                                           const AtomicMathematician::Operator op,
                                           const Expression::Ptr &op2) : PairContainer(op1, op2)
                                                                       , m_op(op)
                                                                       , m_isCompat(false)
{
}

Item ArithmeticExpression::evaluateSingleton(const DynamicContext::Ptr &context) const
{
    const Item op1(m_operand1->evaluateSingleton(context));
    if(!op1)
        return Item();

    const Item op2(m_operand2->evaluateSingleton(context));
    if(!op2)
        return Item();

    return flexiblyCalculate(op1, m_op, op2, m_mather, context, this,
                             ReportContext::XPTY0004, m_isCompat);
}

/**
 * Since ArithmeticExpression::flexiblyCalculate() creates Expression instances
 * at runtime, we have the problem of having SourceLocationReflections for them
 * in the case that we run into a runtime error, since the locations are always
 * located at compile time.
 *
 * This class simply delegates the reflection over to an existing expression.
 *
 * I only managed to trigger this with "current() + 1", where current()
 * evaluates to an invalid representation for @c xs:double.
 *
 * @since 4.5
 * @author Frans Englich <[email protected]>
 */
class DelegatingReflectionExpression : public Literal
{
public:
    DelegatingReflectionExpression(const Item &item,
                                   const SourceLocationReflection *const reflection) : Literal(item)
                                                                                     , m_reflection(reflection)
    {
    }

    virtual const SourceLocationReflection *actualReflection() const
    {
        return m_reflection;
    }

private:
    const SourceLocationReflection *const m_reflection;
};

Item ArithmeticExpression::flexiblyCalculate(const Item &op1,
                                             const AtomicMathematician::Operator op,
                                             const Item &op2,
                                             const AtomicMathematician::Ptr &mather,
                                             const DynamicContext::Ptr &context,
                                             const SourceLocationReflection *const reflection,
                                             const ReportContext::ErrorCode code,
                                             const bool isCompat)
{
    if(mather)
        return mather->calculate(op1, op, op2, context);

    /* This is a very heavy code path. */
    Expression::Ptr a1(new DelegatingReflectionExpression(op1, reflection));
    Expression::Ptr a2(new DelegatingReflectionExpression(op2, reflection));

    const AtomicMathematician::Ptr ingela(fetchMathematician(a1, a2, op, true, context, reflection, code, isCompat));

    return ingela->calculate(a1->evaluateSingleton(context),
                             op,
                             a2->evaluateSingleton(context),
                             context);
}

Expression::Ptr ArithmeticExpression::typeCheck(const StaticContext::Ptr &context,
                                                const SequenceType::Ptr &reqType)
{
    m_isCompat = context->compatModeEnabled();

    const Expression::Ptr me(PairContainer::typeCheck(context, reqType));
    const ItemType::Ptr t1(m_operand1->staticType()->itemType());
    const ItemType::Ptr t2(m_operand2->staticType()->itemType());

    if(*CommonSequenceTypes::Empty == *t1 ||
       *CommonSequenceTypes::Empty == *t2)
    {
        return EmptySequence::create(this, context);
    }

    if(*BuiltinTypes::xsAnyAtomicType == *t1    ||
       *BuiltinTypes::xsAnyAtomicType == *t2    ||
       *BuiltinTypes::numeric == *t1            ||
       *BuiltinTypes::numeric == *t2)
    {
        /* The static type of (at least) one of the operands could not
         * be narrowed further than xs:anyAtomicType, so we do the operator
         * lookup at runtime. */
        return me;
    }

    m_mather = fetchMathematician(m_operand1, m_operand2, m_op, true, context, this,
                                  ReportContext::XPTY0004, m_isCompat);

    return me;
}

AtomicMathematician::Ptr
ArithmeticExpression::fetchMathematician(Expression::Ptr &op1,
                                         Expression::Ptr &op2,
                                         const AtomicMathematician::Operator op,
                                         const bool issueError,
                                         const ReportContext::Ptr &context,
                                         const SourceLocationReflection *const reflection,
                                         const ReportContext::ErrorCode code,
                                         const bool isCompat)
{
    ItemType::Ptr t1(op1->staticType()->itemType());
    ItemType::Ptr t2(op2->staticType()->itemType());

    if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1)
       || (isCompat && (BuiltinTypes::xsString->xdtTypeMatches(t1)
                        || BuiltinTypes::xsDecimal->xdtTypeMatches(t1))))
    {
        op1 = Expression::Ptr(new UntypedAtomicConverter(op1, BuiltinTypes::xsDouble));
        /* The types might have changed, reload. */
        t1 = op1->staticType()->itemType();
    }

    if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2)
       || (isCompat && (BuiltinTypes::xsString->xdtTypeMatches(t1)
                        || BuiltinTypes::xsDecimal->xdtTypeMatches(t1))))
    {
        op2 = Expression::Ptr(new UntypedAtomicConverter(op2, BuiltinTypes::xsDouble));
        /* The types might have changed, reload. */
        t2 = op2->staticType()->itemType();
    }

    const AtomicMathematicianLocator::Ptr locator
        (static_cast<const AtomicType *>(t1.data())->mathematicianLocator());

    if(!locator)
    {
        if(!issueError)
            return AtomicMathematician::Ptr();

        context->error(QtXmlPatterns::tr(
                       "Operator %1 cannot be used on type %2.")
                       .arg(formatKeyword(AtomicMathematician::displayName(op)))
                       .arg(formatType(context->namePool(), t1)),
                       code, reflection);
        return AtomicMathematician::Ptr();